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CN-119463673-B - Waterproof polyurethane coating and preparation method thereof

CN119463673BCN 119463673 BCN119463673 BCN 119463673BCN-119463673-B

Abstract

The application belongs to the technical field of surface treatment agent production, and discloses a waterproof polyurethane coating, which comprises polyurethane emulsion and inorganic filler filled in the polyurethane emulsion, wherein the inorganic filler is inorganic filler modified by a silane coupling agent, the inorganic filler is at least one selected from calcium carbonate, kaolin, barium sulfate, magnesium oxide, calcium oxide, wollastonite, talcum powder and mica powder, the silane coupling agent is at least one selected from KH540, KH550, KH560 and KH570, the mass ratio of the inorganic filler modified by the silane coupling agent to the polyurethane emulsion is 1:8-10, micropores and defects in polyurethane are filled by the addition of the inorganic filler, so that the moisture permeation channel is reduced, the compactness of the material is improved, and part of the inorganic filler has a good shielding effect, so that water molecules can be blocked from permeating into the polyurethane, and the waterproof performance is enhanced.

Inventors

  • GUAN ZHONGXIANG
  • Yao Wenpei
  • TANG YANPING
  • YANG ZHE

Assignees

  • 清远市美佳乐环保新材股份有限公司

Dates

Publication Date
20260508
Application Date
20241031

Claims (8)

  1. 1. The waterproof polyurethane coating is characterized by comprising polyurethane emulsion and inorganic filler filled in the polyurethane emulsion, wherein the inorganic filler is modified by a silane coupling agent; The inorganic filler is at least one selected from calcium carbonate, kaolin, barium sulfate, magnesium oxide, calcium oxide, wollastonite, talcum powder and mica powder; The silane coupling agent is a mixture of KH540 and KH550, and the mass ratio of KH540 to KH550 is 2.5:1 The mass ratio of the inorganic filler modified by the silane coupling agent to the polyurethane emulsion is 1:8-10.
  2. 2. The waterproof polyurethane coating according to claim 1, wherein the inorganic filler is a mixture of kaolin, barium sulfate and calcium oxide, and the mass ratio of the kaolin, the barium sulfate and the calcium oxide is 2-3:1:0.5-1.
  3. 3. The waterproof polyurethane coating according to claim 1, wherein the modified inorganic filler is prepared by mixing an inorganic filler and a silane coupling agent according to a mass ratio of 1:1.5-2, placing the mixture in an ethanol solvent, reacting for 1-3 hours at 100-115 ℃, and then drying the mixture to obtain the inorganic filler modified by the silane coupling agent.
  4. 4. The waterproof polyurethane coating according to claim 1, wherein the polyurethane emulsion comprises the following components in parts by mass: 40-60 parts of polyester polyol; 15-30 parts of isocyanate; 2-5 parts of dihydric alcohol; 1-5 parts of 2, 2-dimethylolpropionic acid; 50-90 parts of a solvent; the isocyanate is a mixture of diisocyanate and long-chain isocyanate, and the carbon number of a long-chain alkyl group in the long-chain isocyanate is not less than 12; And the mass ratio of the diisocyanate to the long-chain isocyanate is 10-12:1.
  5. 5. The waterproof polyurethane coating according to claim 4, wherein the diisocyanate is at least one selected from toluene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and xylylene diisocyanate; the long-chain isocyanate is at least one selected from dodecylbenzene-2, 4-diisocyanate, 1, 12-diisocyanato tridecane, dodecyl isocyanate, tetradecyl isocyanate and octadecyl isocyanate.
  6. 6. The waterproof polyurethane coating according to claim 4, wherein the polyester polyol is at least one selected from the group consisting of polyethylene adipate glycol, polybutylene adipate glycol, and polycaprolactone glycol.
  7. 7. The waterproof polyurethane coating according to claim 4, wherein the dihydric alcohol is at least one selected from the group consisting of propylene glycol, butylene glycol, pentylene glycol, hexylene glycol; the solvent is selected from any one of toluene and acetone.
  8. 8. A process for preparing a waterproof polyurethane coating as claimed in any one of claims 3 to 7, characterized by comprising the steps of: Step 1, mixing an inorganic filler and a silane coupling agent according to a mass ratio of 1:1.5-2, placing the mixture in an ethanol solvent for reaction for 1-3 hours at a temperature of 100-115 ℃, and then drying to obtain the inorganic filler modified by the silane coupling agent; Step 2, mixing polyester polyol, isocyanate and a solvent to react for 2-5 hours at the temperature of 70-90 ℃ to obtain an intermediate I; step3, dissolving 2, 2-dimethylolpropionic acid in a solvent, and then reacting the solvent dissolved with 2, 2-dimethylolpropionic acid with the intermediate I to generate an intermediate II; Wherein the mass of the solvent in the step 2 is 70-85% of the total mass of the solvent, and the mass of the solvent in the step 3 is 15-30% of the total mass of the solvent; Step 4, mixing dihydric alcohol with an intermediate II, reacting for 1.5-3 hours at 70-80 ℃, adding triethylamine to perform neutralization reaction for 30-50 minutes, and adding deionized water to emulsify to obtain polyurethane emulsion; and 5, dispersing the inorganic filler modified by the silane coupling agent into polyurethane emulsion to obtain the waterproof polyurethane coating.

Description

Waterproof polyurethane coating and preparation method thereof Technical Field The application relates to the technical field of surface treatment agent production, in particular to a waterproof polyurethane coating and a preparation method thereof. Background The pure natural leather product is made of protein as a matrix and has strong hydrophilicity and air permeability, and the leather prepared by processing people can be added with a plurality of raw materials containing hydrophilic groups such as hydroxyl, carboxyl, amino, amido and the like in the preparation process, so that the leather has poor waterproof performance and the use of the leather is seriously influenced. Along with the increase of people's demand, the improvement of leather waterproof performance is the target that people pursued always, and as early as 20 centuries, people just through adding substances such as paraffin and animal grease that have the water-proof effects in leather preparation in order to reach the purpose of improving leather waterproof nature, later gradually develop to add the modification link on the leather surface, not only can form the even protection film of one deck on the leather top layer like this, still endow leather beautiful color, can play the effect of reinforcing leather decorative feel, the additional value of leather has obtained effective promotion, is popular and uses gradually. Therefore, the waterproof coating as a leather finishing agent becomes an important link in the leather processing industry, and the development of the waterproof coating is further promoted by the wide application of waterproof leather. With the progress in production and life, people have further demands on the requirements and performances of related products of leather, leather products not only can meet the most basic production and life requirements of people, but also are fashionable and continuously matched with the demands of people in terms of use feeling, so that people hope that leather shows the three-proofing performance which is not possessed by leather such as water resistance, oil resistance and dirt resistance, the fluorine-containing leather waterproof agent meets the demands of people and the demands of production development, and accordingly, the fluorine-containing leather waterproof agent gradually moves into the field of view of the masses, and in order to keep the excellent water resistance and oil resistance of the leather, a layer of uniform waterproof agent coating film is formed on the surface of the leather by using the leather waterproof agent. The fluorine-containing compound can be tightly connected with a carbon chain main chain due to the existence of C-F, has excellent performance which cannot be compared with other materials, is widely applied to the fields of chemical industry, industrial building, aerospace and the like, is also introduced into the preparation process of leather waterproofing agents due to the special excellent performance, is applied to the leather field, and can keep soft texture and better air permeability of leather treated by the waterproofing agents, has three-proofing performance, endows leather, cotton, polyester, nylon and other materials with high durable waterproof effect, and has excellent waterproof and ageing resistance. Chinese patent application 201910940003.6 discloses a fluorine-containing polyurethane material with water-proof, oil-proof and antifouling properties, which is prepared by synthesizing a dihydroxyfluorocarbon chain monomer through a mercapto-vinyl Michael addition reaction, introducing the dihydroxyfluorocarbon chain monomer into polyurethane through an addition polymerization reaction with a polyurethane prepolymer blocked by diisocyanate, and obtaining the fluorine-containing water-based polyurethane material with water-proof, oil-proof and antifouling properties through a chain extension reaction and a neutralization reaction; The fluorine-containing small molecular organic compound in the scheme has the characteristics of water resistance, oil resistance, fouling resistance, heat resistance and the like, but is easily bonded with proteins in blood, is enriched in a human body to influence the health of the human body, and the fluorine-containing polymer still basically keeps the characteristics of the fluorine-containing small molecular organic compound and has good biocompatibility, and meanwhile, the chemical activity and the biological activity of the fluorine-containing small molecular organic compound are low, so that the health of the human body is not influenced. The fluorine-containing small molecular organic compound is introduced into the polyurethane material, so that the performances of water resistance, biocompatibility and the like of polyurethane can be well improved, and the toxicity of the fluorine-containing small molecular organic compound can be remarkably reduced. Therefore, the scheme is that fluorine is dope